The M 2 factor of a laser beam limits the degree to which the beam can be focused for a given beam divergence angle, which is often limited by the numerical aperture of the focusing lens. Smaller values of M 2 are physically not possible.Ī Hermite–Gaussian beam, related to a TEM nm resonator mode, has an M 2 factor of (2 n + 1) in the x direction, and (2 m + 1) in the y direction. air).Ī laser beam is often said to be “ M 2 times diffraction-limited”.Ī diffraction-limited beam has an M 2 factor of 1, and is a Gaussian beam. Where w 0 is the beam radius at the beam waist and λ the wavelength in the medium (e.g. In other words, the half-angle beam divergence is The M 2 factor, also called beam quality factor or beam propagation factor, is a common measure of the beam quality of a laser beam.Īccording to ISO Standard 11146, it is defined as the beam parameter product divided by λ / π, the latter being the beam parameter product for a diffraction-limited Gaussian beam with the same wavelength.
How to cite the article suggest additional literature You may also get a training course for your team on issues like laser beams, beam quality and other aspects of lasers.ĭefinition: a parameter for quantifying the beam quality of laser beamsĬategories: general optics, optical metrology requirements for specific applications or measurement techniques. Encyclopedia > letter M > M 2 factor M 2 Factor Advice on Laser Beam QualityĪsk RP Photonics for any advice concerning laser beam quality, e.g.
0 kommentar(er)
